About this wiki page

This wiki page is intended to be a relatively quick-start / key reference guide to Debian Systems Administration
for experienced Linux SysAdmins that are inexperienced or less experienced with Debian Systems Administration.
It is written, at least in part, by Debian SysAdmins with as much 20 years or more of Debian SysAdmin experience,
so hopefully one will find key useful information/advice/pointers/references here - and potentially avoid many common problems, missteps incorrect presumptions/assumptions, etc.

Note: this wiki page is a work-in-progress. Although much has been relatively flushed out with relevant information, there remains relevant bits missing, etc. to be (much more) completed.
Note also - anchor tags (/titles within page) may still be in a state of flux - so wouldn't recommend linking to them ... yet. However, am expecting the page URL to remain the same (or redirect to same), so expecting that to be persistent and okay to link to.



Debian: Quick Start Guide / Basic "Care and Feeding"

So, presuming one is already rather to quite familiar with Linux Systems Administration, but not, or not so familiar with Debian Systems Administration, and let's say one already has Debian system(s) installed that one needs to take care of and maintain.
Here are some most critical bits to get one started with Debian (more complete information can be found further below in other sections):

Don't Break Debian

What is Debian ? / Why choose Debian?

Unique* to Debian

*mostly,
and in brief, unique to Debian:

Debian Pros "vs." Cons

Feature/Consideration

Debian Pros

Debian "Cons"

quality

very high

What, you want more bugs to troubleshoot/fix?

software

more than 59,000 ready-to-use software packages, lots of options, mostly not forced by someone else's choices

Can't have everything installed at same time (e.g. some packages conflict), lots of choices

stability

stable is highly stable

full support "only" about 3+ years

governance/control

Democratic/Meritocracy by Debian Developers, no (benevolent?) dictator/overlord/CEO to change all

no (benevolent?) dictator/overlord/CEO to change all

installed base

more Linux distros are Debian or based upon Debian than any other existing

can't brag about your special snowflake boutique distro

flexible

broad package selection & architecture support suitable to wide variety use cases

not highly optimized to certain specific edge cases

company / commercial entity?

not - can't be bought/sold, always free, can't be bought out

can't buy it out

Debian support

excellent & free

Internet-only, no toll-free number, volunteers, not much hand-holding, no babysitting nor butt kissing

support lifecycle length

about 3+ years, LTS about 5, more with ELTS

exact end dates not highly predictable long in advance, LTS supports less, ELTS even less

most recent software / "rolling" release

stable+backports, testing, unstable

full support limited to stable (and oldstable for while), not Debian's primary focus/recommendation

freedom/free

Absolutely! Social Contract & DFSG

Don't get non-free by default, but can be added

easily know/determine software free/freedom

Absolutely! non-free not enabled by default

non-free not enabled by default

highly predictable release schedule

kind'a - freezes have schedule, releases projected, releases happen when darn good and ready

releases don't come out like clockwork per some highly predictable schedule well in advance

3rd party support

available

mostly not highly commonly used nor large, generally not free

3rd party / non-Debian software

can be installed/managed (e.g. via alien)

not as purpose-built for or as commonly used for installing lots of 3rd party software

Debian: Evaluating, Choosing, and Choices

Support / Security / Lifecycle

What is supported, and for how long?

The short approximation is roughly:

More complete/accurate details:

Lifecycle

Debian has what it calls distributions, as in a Debian distribution.
This (distribution) usage is distinct from, and one should, in context specific to Debian, avoid confusion with other highly common usage of distribution in more general context of Linux, notably that of a Linux distribution.

To clarify and distinguish the two:

Debian always has at least three releases/distributions in active maintenance: stable, testing and unstable, there's also oldstable, oldoldstable, etc. - see relevant support information elsewhere on this wiki page.

Releases: names and numbers, etc. (see also further above regarding support):

Getting help/support

Package Management

.deb format files

The .deb format is the Debian binary package file format.
This doesn't mean one can willy nilly grab and install any and all .deb format files and expect good results - or even not to break things. One should only install appropriate trusted files - e.g. from Official Debian repositories and appropriate release - see also "how to not break Debian" further above. Note that when one installs a .deb package, one is entrusting the full integrity of the host system to that software, hence the importance of it being known good software from an appropriate trusted compatible source.

What about .rpm and other package format files?

Debian natively uses .deb files. Directly installing .rpm files - e.g. such as by using the rpm command, is almost assuredly a way to break Debian and cause problems. Notably, even though Debian does make rpm command available to be installed, if one installs using rpm command, that happens completely outside of Debian's package management system, and thus Debian's package management system will be completely unaware of such, and various conflicts, breakage, etc. is likely to occur (and likewise rpm knows nothing of Debian's package management system). If one has need to install an otherwise suitably compatible .rpm package on Debian, the way to do that is by use of Debian's alien(1p) program - which is capable of converting among a fair variety of package formats (including .rpm) and .deb, and one can thus convert package to .deb, and then install it under Debian's package management system - and it will be suitably tracked, conflicts avoided, dependencies checked for, etc. Note, however, in most cases, one would do well to first check if Debian already has and provides quite the same/similar functionality in package(s) directly provided by Debian - some reasonable searches may be useful too - often the name of the package in Debian may be somewhat different, as the package may be named differently for reason(s), or might be part of some other package that combines functions/capabilities, or may be split across multiple packages (e.g. to separate out a huge documentation component, so it may optionally and independently be installed, or not installed, or to break apart a huge collection of functionality and programs, in to more modular sets, where one may more selectively pick and choose what to, and not to, install).

Advanced Package Tool (or APT)

apt - apt and friends is mostly what one wants to and should use for Debian package management
Most notably, the APT system and its programs and programs that use it, very well handle dependencies (e.g. being able to also retrieve and install all needed dependencies), conflicts (informing/warning of such, and generally offering potential solution or choices of possible solutions), in addition to the tracking done at lower levels (see also dpkg further below). APT also has much configurability and many advanced features/capabilities often not matched by otherwise similar tools on other distros.
See also: Debian: basic "care and feeding" / quick start guide
further above, but some more of a brief introduction to APT and many typical/common commands:

dpkg

The dpkg command, is the low level tool/program for dealing with Debian packages. Most of the time one will deal with Debian packages at a higher level, using some tool that is or utilizes that APT system. Regardless, sometimes dpkg comes in quite handy for certain simple operations, or in relatively rare circumstances (e.g. such as replacing apt, or dpkg itself) it may become necessary to use dpkg. Note also that the higher level tools generally call and use dpkg - so they will also do things such as, at least by default, log relevant dpkg actions (e.g. in /var/log/dpkg.log). While mostly using programs that utilized the APT system, here are some dpkg commands that typically will still remain quite handy:

sources.list file(s)

/etc/apt/sources.list (and also any files under /etc/apt/sources.list.d/) configures what repository(/ies) Debian uses.
sources.list

Installing

Upgrading

regular maintenance upgrades

major upgrades

Debian very well handles doing major release version upgrades (and has for decades, unlike at least some other distros).
Do, however, be sure to first read the relevant documentation and prepare ahead of time, most notably one should read and pay careful attention to the release notes, and also be sure to read the installation guide documentation.

See Also / References


CategorySystemAdministration